Kamworks is a social business in Cambodia that designs and assembles solar products locally, including PAYGO solar home systems. They have installed over 300 GSM-enabled solar home systems that allow remote monitoring and control of the systems using mobile networks. Customers can pay for the systems in installments using their mobile phones. Lessons learned include customers preferring to eventually own rather than rent systems, liking using mobile money for payments, and partnerships with organizations like microfinance institutions being important but taking time to develop. Remote monitoring of systems has been promising but control via GSM has faced challenges. Kamworks aims to accelerate sales in Cambodia and become a broader PAYGO solutions provider.